Neoadjuvant chemotherapy is one of the standardized treatment methods for breast cancer. Pathological assessment and standardized evaluation after neoadjuvant therapy are very important. The main differences between the different criteria of pathological assessments are their definitions of pathologic complete response (pCR), which is currently generally defined as ypT₀/is ypN₀, that is, residual ductal carcinoma in situ in the breast after chemotherapy, without residual cancer cells in the axillary lymph nodes. This paper introduces the histological response criteria of the Japanese Breast Cancer Society and compares it with the Residual Cancer Burden system of MD Anderson Cancer Center, the Millar and Payne method of the United Kingdom, and the pathologic evaluation standard recommended by Tianjin Cancer Hospital. A large number of clinical studies show that the DFS and OS of breast cancer patients with pCR are significantly higher than those of non-pCR patients after neoadjuvant chemotherapy. However, pCR has different meanings in different breast cancer subtypes and pCR may not be the only predictor in neoadjuvant chemotherapy.